The present invention relates generally to building entry and exit doors and more particularly to an articulated overhead door constructed of blow-molded material sections for garages, warehouses, and factories.
Over the last several years, a number of entry and exit door devices have been developed to provide for the user movable door means through which an entry aperture can be opened and closed. While several of these door assemblies provide building structures secure protection from the elements, few if any, address themselves to the advantages that an articulated overhead garage door constructed of blow-molded plastic sections render. The conventional door devices examined in the prior art, for the most part provide a movably operable door capable of covering a large entrance which has the strength to protect the building enclosure on which it is installed. Of these door assemblies examined, however, most refrain from teaching towards the improvements of 1) better insulation, 2) durability, 3) ease in maintenance, 4) reduction in weight for improved mechanical and power control, 5) explosion proof construction yielding uni-directional give, 6) improved security, 7) resistance to denting and chipping, 8) facilitated replacement of parts, and 9) ease in installation. The present articulated overhead door which is constructed of blow-molded material sections more adequately achieves these advantages which conventionally constructed doors have to date found difficult to accomplish.
One such conventional door examined in the prior art is disclosed in the Ogden U.S. Pat. No. 974,699 door and means for operating same. The Ogden door assembly provides for a door of conventionally constructed panel sections constructed in such a way as to fold the door up above the doorway rather than sliding the door along rails along the doorway. While the patent discloses one of the earlier articulated vertically moving doors, each section pivots at its top or bottom so as to swing inwardly into the building enclosure to which it is attached. The panel sections in the Ogden assembly are pivotally connected at their opposite ends to adjacent sections whereby the sections are arranged in a free swinging relation. The door in its entirety has each panel zig-zag as the door is opened rather than having all panels smoothly following one route during the opening and closing operations.
The door disclosed by Dautrick U.S. Pat. No. 1,603,379 discloses an assembly utilizing the more universally accepted vertical movement technique in which each panel of the door slides along rails in much the same way as most conventionally used garage doors. In this device, rollers on each end of the entire door are guided by a rail track which converts the positioning of the door from that of being vertical in the closed position to that of being substantially horizontal in the open position. Unlike Ogden, the panels follow one another in the movement of the door and do not zig-zag with respect to each other thus avoiding a stacking up of the door panels over the immediate entrance to the building enclosure. For the most part, the Dautrick door addresses itself to the use of counterweights in combination with a door that moves through a pre-determined path, to overcome the opening and closing resistance offered by the weight of the door. Dautrick's counterweighting device utilizes flexible chain-like members linked hingedly to one another which are designed to become ineffective as counter-weighting means, as the panels travel along a pre-determined path.
The door construction device disclosed by Cook, et al. U.S. Pat. No. 1,832,966, features still yet another type of articulated overhead door. Rather than sliding along rails from a vertical position to a substantially horizontal position over the building enclosure, the Cook, et al patent discloses a door that utilizes scissor-type tongs to effectuate movement. The section panels comprising the articulated door in the Cook, et al patent do not hinge to one another nor follow one another in a pre-determined path. The panels instead stack up one alongside one another when the door is opened requiring disconnection of one panel from another. The door in its entirety utilizes panels which are connected by linkage arm devices which in turn respond to the movement of the linkages comprising the scissor-type tong assembly. The panels thus overlap one another in a position proximate to the entry to the building enclosure itself. This particular device additionally discloses a motorized means for activating movement of the scissor-type tong linkage.
A door controlling means is disclosed in Rush U.S. Pat. No. 1,938,978. The Rush device comprises a spring controlling means working in operation with an articulated overhead type of door usually of the fire-door variety. The spring control means counter-balances a door when it is in the open position. A switching means attached to the counter balancing spring removes the counter balancing effect of the spring means and thus releases the door into a closed position. The switching means associated with release of the spring counter balancing means is so constructed in the Rush device to provide decreasing resistance as a function of time. This enables closure of the door at a moderate rate so as to avoid shock or jar of a door crashing closed.
Norberg U.S. Pat. No. 2,093,020, discloses a shiftable door member which automatically enables a garage door to accommodate inclined or slanted surfaces which traverse the garage door width. The Norberg device teaches primarily to a bottom rail attachment which fills in an exposed portion of entrance-way due to a slanted or inclined floor which is unable to meet flushly with the bottom of the garage door.
An overhead garage door keeper is disclosed in Rix U.S. Pat. No. 2,426,052. The key feature in this device is the keeper assembly which not only locks the door in its closed position, but exerts pressure against the upper middle section of the garage door entirety so as to prevent the tendency of warpage and/or sagging of the door, problems often encountered with the doors of conventional construction.
Wolfe U.S. Pat. No. 2,619,165, teaches an overhead door structure which is concerned with the braking system used in preventing the door from moving when it is in the overhead horizontal open position. The braking system utilizes a brake shoe and brake plate which cooperate to hold the door at the open position desired.
A panel hinge construction is taught by D'Orazio U.S. Pat. No. 2,916,089. The D'Orazio articulated door structure utilizes a supporting row of hinges between the panel sections; these hinges traveling the length of the door. It is the purpose of the D'Orazio articulated door to avoid the necessity of utilizing heavy structural means or support frame-work within which the panel sections are inserted. The heavy reinforcing skeleton of the door is made needless by utilizing reinforcing hinges which hinge one entire row of garage panel sections to another entire row and which further protect the edges of the adjoining panel section. Thus, D'Orazio replaces a heavy supportive outer structure on the door with a hinge support structure running the entire width of the door.
An articulated door construction is shown in Howell Sr., U.S. Pat. No. 3,023,804. The Howell Sr. door discloses the use of elongated channel strip members on the lower edge of an articulated door which assist in sealing out the weather, and which provide for quiet operation of the door when the door is being moved into the closed position. The Howell Sr. device similarly attempts to reduce the shock to the door when it is lowered into this closed position while providing a convenient attaching means for the cables attached to the counter-balancing springs or weights.
Other devices have been developed to cooperate with a conventionally constructed door such as the device disclosed in Smith U.S. Pat. No. 3,256,118. The Smith device is an overhead door retaining means which retains the position of the door automatically so as to insure a close fit between the header of a building doorway and the upper edge of the overhead door when the door is in a closed position. The Smith retaining means reinforces the top edge of the door so as to resist external wind pressure and so as to guarantee an avoidance of interference when the door is opened and closed. Another device cooperating with the conventional overhead door is disclosed by Lomaz U.S. Pat. No. 3,226,144. The Lomaz device is an overhead door latch which provides latching means for a door without requiring the precision alignment between cooperating locking elements.
It thus becomes apparent, that the articulated overhead door has been in the prior art for some time together with cooperating elements which have been developed to more efficiently utilize such an overhead door. But the conventional door as developed through the years, has, for the most part, been unable to secure the advantages which the present articulated overhead door enables through its blow-molded fabrication and unusual operating means.
It is an object of the present invention, therefore, to facilitate ease in the manufacture and distribution of articulated overhead doors.
It is additionally an object of the present invention to provide a durable maintenance free overhead door which provides improved insulation for a building enclosure, thus minimizing heating and cooling requirements.
Additionally, it is an object of the present invention to provide for an articulated overhead door of minimal weight to facilitate the mechanical or power driven opening and closing of the door.
It is additionally an object of the present invention to provide security to its user through its "double-thick" design, to be explosion proof since constructed with unidirectional give, and to be dent and chip resistant since the blow-molded construction has a degree of flexibility and won't crack or dismember so easily as conventional overhead doors tend to do.
Finally, it is an object of the present device to facilitate ease in the installation of an overhead articulated door while similarly enabling facilitated replacement of panel sections or hardware associated with the blow-molded fabrication of the door.